1. Field of the Invention
The present invention relates to a laser processing apparatus and method, and more particularly, to a layer processing apparatus and method that can process a hole at an accurate location of a substrate using a laser.
2. Description of the Related Art
In general, a plurality of holes such as via-holes for electric connection between substrates are formed on the substrates.
At this point, thousands to hundreds of thousands of the holes are formed on the substrate. A laser processing apparatus has been most widely used to form many holes on the substrate.
The laser processing apparatus uses a layer processing method including disposing the substrate on the stage, adjusting an angle of the substrate to emit laser beams using a scanner unit, and processing the holes on desired locations in accordance with processing location data that are preset. This method has an advantage of more quickly accurately forming the holes on the substrate as compared with other methods.
However, even when the laser processing method is used, the forming of the holes at the accurate locations is not still enough. A location error of the holes frequently occurs due to a variety of factors.
At this point, one of major factors causing the location error is a case where the preset processing location data are different from the locations of the holes that will be actually formed on the substrate. This occurs as the locations of the holes that will be processed vary due to contraction and expansion of the substrate in a direction by heat and pressure generated during a process for forming a pattern on the substrate.
In addition, the substrate must be accurately moved to a reference point of the processing location data. However, since there is an error due to mechanical limitations of a stage apparatus and when a control value of a laser scanner is not accurate, the error may occur.
As a result, when the processing error with respect to the hole locations occurs, the reliability of the products is deteriorated. In the worst case, the holes may be processed at totally undesired locations and thus the products may not be used.
Therefore, in the processing apparatus and method using the laser processing apparatus, there is a need for techniques that can process holes at accurate locations on the substrate by correcting the error caused by the above-described factors.